Lock stitch sewing machine



July 23, .1935. G. SAUER 2,009,328

\ LOCK STITCH SEWING MACHINE Filed March 19, 1934 5 Sheets-Sheet l July 23, 1935. G. SAUER I 2,009,328

. LOCK STITCH SEWING MACHINE .K

Filed March 19, 1934 5 Sheets-Sheetl 2 w HN i I YQ 1 'N Nx- E i' Eh Ql mw mi a Q Y l July 23, 1935. GQ sAUER Loox STITCH SEWING MACHINE 3 Sheets-Sheet 3 Filed March 19, 1954 Patented July 423, 1935 UNITED lSTATES 009,328 Loox s'rlrcn sEwrNG MACHINE George Sauer, Berwyn, Ill., assignor to Union Special Machine Company, Chicago, Ill., a corporation of Illinois Application March 19, 1934, serial No. 716,416

whims. (Cl. 11a-22o) 5 tive action-of a needle and a rotary hook.

An object of the invention is to provide a maychine of the above type wherein `the actuated parts of the stitch forming mechanism and the actuated parts of the feeding mechanism are each operated from shafts which terminate in the hollow standard and wherein the rotary hook shaft and the feed actuating shaft are independently connected with a main actuating shaft which operates the needle whereby the number of parts and the lost motion incident to the conand 3 and end walls which are formed integral necting of the parts, is reduced to a minimum.

A further object of the invention is to provide a machine of the above type wherein the transmitting mechanism is so constructed that the number of intermeshing points between the driving gear and the parts actuated thereby are reduced to a minimum.

In the drawings- Figure 1 is a viewr in vertical section through a machine embodying the improvements;

Fig. 2 is a view partly in horizontal section and partly in plan from above the work support, with parts of the Work support broken away to show the structure beneath the same, and

Fig. 3 is an end elevation as viewed from the right in Fig. 1, with parts broken away to show the' driving mechanism within the hollow standard.

The invention relates to a sewing machine for forming'lock stitches. The stitches are produced by a reciprocating needle and a cooperating rotating hook with which is associated a thread carrying bobbin of the usual type'. The material is fed across the work support by a feeding mechanism which includes a feed dog carried byv a feed bar which is moved endwise for feeding the fabric and which is raised and lowered for producing the feed cycle. y The needle bar is operated by the main actuating shaft Ywhich extends through a hollow arm overhanging the work support. This arm is carried by a hollow standard. 'I'he work support is preferably formed integral with the standard and disposed at a point above the lower end of the standard. As herein shown the standard is closed at its lower end so as` to provide an oil sump. 'I'he shaft for operating the feeding mechanism extends longitudinally of the work support and through the wall of the hollow standard into the standard. The shaft which operates the rotary hook likewise extends longitudinally of the work support and through the wall of the hollow standard into the standard. There is a transmitting gear in the hollow standard which meshes with a gear on the main actuating shaft which reciprocates the needle bar. 'I'here is a gear on the feed shaft which meshes with the transmitting gear and there is likewise a. gear on the rotary hook shaft which meshes with the transmitting gear so that the feed actuating shaft and the rotary hook shaft are independently driven from the transmitting gear.

Referring more in detail to the drawings, the invention is shown as applied to a ,sewing machine which includes a standard I, which is hollow `Iand which is provided with depending side walls 2 therewith, as shown in Fig.' 2. The bottom end of the standard is closed by a plate 4, which is attached to the standard so as to provide an oiltight joint, thus permitting a bath of oil to be maintained at the lower end of the standard. Formed integral with this standard is a supporting bed or work support 5. 'Ihis work support 5 is connected to the standard at a point above the lower end thereof or it may be said that the standard has a portion which extends below the work support. The standard is hollow and supports an arm 6 which overhangs vthe work support. The arm forms an extension of the hollow standard.

At the outer end of the overhanging arm is a needle head 1, in which a needle bar v8 reciprocates. Said needle bar carries a needle 9. Extending through the overhanging arm is the main actuating shaft III which is mounted in a bearing I I at its outer end and in a bearing I2 at the standard end thereof. Atthe outer end of this shaft I0 is a crank disk I3 carrying a crank which is connected to the link I4, and the link I4 is in turn connected to the needle bar. Thus it is that the rotation of the'. s haft I0 will reciprocate the needle bar.

Located beneath the work support and cooperating with the needle is a rotary hook I5 carried by a shaft I6. The shaft I6 rotates in a bushing I1 mounted in a bearing lug I8. This shaft also depending lug I8 and also in a bushing 3I carried by the innerv wall 2 of the standard. On the shaft 23 is an eccentric, with which an eccentric strap 24 cooperates. The eccentric strap carries a rod 25 which has a telescoping engagement with a sleeve 26, which sleeve in turn is pivotally connected to the feed rocker. Attached to the sleeve 26 Vis a link 21 which is mounted for oscillation on an arm 28 carried by a shaft 29 which is capable of adjustment to different set positions. As the eccentric rotates, it Will impart a sliding movement of the lrod into and out of the sleeve, which is an idle movement and it will also impart a lateral movement to the sleeve 26. The lateral movements of the sleeve 26 through the link 21, are converted into an endwise movement of the arm 26 and this is what moves the feed bar back and forth. The feed bar is raised and lowered by an eccentric strap 30 cooperating with an eccentric on the end of the shaft 23 and connected in the usual manner to the feed bar. This feeding mechanism forms no part of the present invention, but is shown and described in the application filed by George Sauer and Clarence C. Smith, on May 31, 1933, Serial No. 673,738.

The shaft I6 extends through an opening into the hollow standard and the bushing I9 closes the opening. N The shaft 23 also extends through an opening in the standard and the bushing 3I closes this open/ing so that the lower end of the standard is completely closed and the ends of the two shafts I6 and 23 projecting into the hollow stand.- ard. At the end of `the shaft 23 within the standard, -is a gear 32. This gear meshes with a gear 33 having a hub 34 which is mounted for rotation on a xed shaft 35. There are collars 36, 36 fixed to the shaft and located at each side of the hub for maintaining the rotating position of the gear 33 thereon. On the main actuatingshaft I6 is a gear 31 which is xed to the shaft and which meshes with this transmitting gear 33. As the mainl actuating shaft rotates, it will through these intermeshing gears impart a rotation to the feed shaft and thus the feed dog is given its feeding movements through this single shaft and the gearing connection with the main actuating shaft. The gears 32 and 31 are so dimensioned that the main actuating shaft and the feed shaft rotate in the same timing and impart a feeding movement to the fabric foreach stitch formation.

Mounted on the end of the shaft I6, which projects into the hollow standard, is a gear 38. 'I'his gear 38 is located so that it overlaps in part the gear 32`. The transmitting gear 33 is of sufficient width so that both the gears 32 and 38 mesh therewith. One reason for placing these gears 32 and 38 so that they overlap in part, is to bring the shafts I8 and 23 relatively close together. The rotary hook shaft has its longitudinal axis lying in a vertical plane containing the path of reciprocation of the needleand the feed shaft has its axis lying in a vertical plane slightly in rear of Y.

the stitching point and at the most advantageous position for lifting the feed bar. Another reason for placing the gears 32 and 38 so that they overlap in part, is to bring said gears into mesh with a different section of the teeth on the transmitting gear. -It is particularly essential that the rotations of the hook relative to the reciprocations of the needle be maintained so that a hook will pass the needle at the exact point in its path of reciprocation in order to take the needlel thread loop therefrom. There is very much less strain on the driving gearsfor the rotary hook than on the driving gears for the feed, as the feed dog which moves intermittently, at one part in its cycle, not only moves the fabric, but it lifts the farbric off from the work support against the heavy tension of the spring on the presser foot. During its return cycle, the feed dog is free from these strains, and therefore, the strain on the feed shaft is an intermittent strain, causing greater wear on the teeth of the gear carried by the feed shaft. While possibly the Wear on the teeth of the transmitting gear, through its contact with the actuating gear, is substantiallly uniform, the Wear on the portions of the teeth which contact with and operate the hook, will be less than on the gear which operates the feed, and when the rotary hook has a direct geared connection with the needle actuating shaft, which is independent of the feed, a better timing is maintained. Furthermore, the transmitting gear is provided with a number of teeth which is not a multiple of the teeth in the gears with which it meshes, so that there is a progressive shifting movement whereby the tooth or teeth in either gear 32, 31 or 38 which is subject to the special strain, will nd itself in contact successively with a different tooth in a transmitting gear. A still more effective distribution of wear is obtained by making the material of the teeth of the transmitting gear softer, than the material of the teeth of the other gears, as `for example, of bakelite. The greatest wear will be taken by the transmitting gear and thus Will be distributed on all of the teeth. This arrangement of the teeth in the driving train of gears, and the general type of machine to whichthis invention is applied, is shown and described more fully in the application of Norman V. Christensen and Charles F. Rubel, led May 9, 1933, Serial No. 670,186.

The gear 38 is so dimensioned that the rotary hook shaft will be given two rotations for eacli rotation of the feed shaft. The gear 32 rotates in a position well down toward the lower end of the standard. The' oil sump at the lower end of the standard is filled with oil, so that the lower portion of this gear 32 extends beneath the surface of the bath of oil. This will hand up the lubricating oil onto the gear 33 and the gear 31 and in turn the gear 38 will also be lubricated. While the invention is described as embodied in a sewing machine having a hollow enclosed standard, with an oil sump for lubricating the intermeshing gears,k it will be understood that from certain aspects of the invention, the driving mechanism for the needle, the feed and the looper, which is shown and described, may be used in other types of machines. It is also obvious that minor changes in the details of con-- structionmay be made without departing from the spirit of the invention as set forth in the appended claims.V a

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is-

1. A sewing machine includingA in combination, a standard, a work support, an arm overhanging the work support, a. needle bar carried by said arm, 'a feeding mechanism and a rotary hook beneath the work support, a transmitting gearcarried by theA standard, an actuating shaft for the needle bar geared to the transmitting gear, another actuatlng shaft for the feeding mechanism directly geared to the transmitting gear, and another actuating shaft for the rotary hook directly and independently geared to the transmitting gear. I

2.. A sewing machine including in combination,

a standard, a work support, an arm overhanging the work support, a needle bar carried by said arm, an actuating shaft carried by said arm and connected to said needle bar, a feeding mechanism and a rotary hook beneath the work support, a transmitting gear carried by the standard, a gear on the actuating shaft for the needle bar meshing with said transmitting gear, an actuating shaft for the feeding mechanism, a gear carried by said shaft in said standard and meshing with said transmitting gear, an actuating shaft for the rotary hook, a gear carried by said 'last-named actuating shaft in the standard and the feed shaft and the gear actuating the rotary hook, said gears actuating the feed shafts and the rotary hook being disposed so as to mesh with different sections of the teeth of the transmitting gear.

3. A sewing machine including in combination a hollow standard closed at its lower end, a work support connected thereto and disposed above the lower end of the standard, an arm carried by the standard and overhanging said work support, a needle bar mounted for reciprocation on said arni, an actuating shaft for the needle bar mounte on said arm and extending into said standard, a feeding mechanism beneath the work support, an actuating shaft therefor disposed beneath the work support and extending into said vhollow standard, a rotary hook'beneath the work support, an actuating shaft therefor extending into said hollow standard, means located within the hollow standard and having operative connection with the actuating shaft in the v t said arm, an actuating shaft for the needle bar mounted on said arm and extending into said standard, a gear mounted on said actuating shaft in said hollow standard, a transmitting gear mounted in said hollow standard and meshing with said gear on the actuating shaft, a feeding mechanism beneath the Work support, an actuating shaft therefor disposed beneath the work support and extending into the hollow standard, a gear carried by said shaft in said standard meshing with said transmitting gear, a rotary hook beneath the work support, an actuating shaft therefor extending into said hollow standard, a gear carried by said last-named shaft in said standard and meshing with said transmitting gear whereby said rotary hook shaft is operated independently of the feed shaft from said transmitting gear.

GEORGE SAUER. 

